Archdevil Asmodeus of Nessus

"I literally sit beneath eight tiers of scheming, ambitious entities that represent primal law suffused with evil. The path from this realm leads to an infinite pit of chaos and evil. Now, tell me again how you and your ilk are the victims in this eternal struggle." - Asmodeus addressing the Celestial Jury.

The Lord of the Ninth and ruler of Baator, Asmodeus is one of the most dangerous and powerful beings in the known Multiverse. While his overall strength may not be as prominent as many of the other deities, his true power and deadly nature come from his overwhelming intelligence. A master manipulator, and an expert at deception, the schemes of Asmodeus span millennia as he prefers to deceive his enemies into their own destruction rather than direct confrontation, although his actual power should not be underestimated. An enigma in the cosmic hierarchy, Asmodeus is not a true deity, yet neither is he mortal, he merely is.

Whoever he was before is not only hidden, but erased, all that is known of Asmodeus is that what he wants you to know...

Ruby Rod of Asmodeus. Gifted to Asmodeus by Primus, the ruby rod is a sign of the devils of the Nine Hells' innate abilities to be able to make pacts and keeps Asmodeus from breaking his deals.The ruby rod of asmodeus is +5 epic artifact (included in the attack) that does an extra 36 (8d8) cold, fire, or acid damage, Asmodeus’ choice, on a hit and double damage to celestials. In addition, it has 15 charges, and any of its properties that require s saving throw have a save DC of 22, +16 to hit with attack spells. While holding it, Asmodeus can use an action to cast arcane eye, bestow curse, fire shield. Alternatively, he can spend 1 charge to cast one of the following spells from it (at 9th level and double the area/range): cone of cold, lightning bolt, delayed blast fireball. In addition, when he hits a creature in a melee attack with the rod he can choose to immediately spend 2 charges to cast dominate monster on the target. The wand regains 1d8 + 4 charges daily at dawn.

While Asmodeus is in possession of the rod he is able to summon twice the number of devils, (see summon devil in actions) or double is chance of summoning a duke-of-hell or an archduke.

(This stat block was adapted from the pdf Epic Monster Updates: A Guide to Epic Threats in 5E).

Overlord of Hell. Asmodeus is the supreme ruler of the Nine Hells. This title has power and his might is greater anywhere in the Nine Hells. While on Baator, Asmodeus is considered CR 35 (265,000 XP) and he gains the following attributes:

• Asmodeus can use 6 legendary actions.
• Asmodeus rolls a critical hit on a natural 19-20.
• Asmodeus regains 30 hit points at the start of his turn.
• Asmodeus can, 2/day, use an action or legendary action to teleport anywhere in Baator.
• Asmodeus can, on an initiative count of 20 (losing initiative ties), use any of the domain actions available to the lord of the layer of Hell he is on.

Lord of Nessus. Like all of the Nine, Asmodeus’ title has power and his might is greater while he is in his domain. While on Nessus Asmodeus is considered CR 37 (315,000 XP) and he gains the following attributes:

• Asmodeus can use 7 legendary actions.
• Asmodeus has advantage on all attack rolls.
• Asmodeus rolls a critical hit on a natural 17-20.
• Asmodeus regains 60 hit points at the start of his turn.
• Unless Asmodeus wishes to be affected, he is immune to spells of 5th level or lower and has advantage on savings throws of all spells and magical effects.

Domain Actions:

While anywhere within the plane of Nessus, Asmodeus can take a domain action as long as he is not incapacitated. On initiative count 20 (losing initiative ties), Asmodeus can draw on the infernal power Nessus to take a domain action to cause one.

• Asmodeus teleports (3/day) to any location in Nessus.
• While Asmodeus is wielding the Ruby Rod he can (1/day) encase himself in a 10-foot-radius spherical wall of force. The area 50 feet around the sphere (but not within it) becomes an antimagic field. This effect lasts for 3 rounds. In the first round, Asmodeus is purged of any unwanted enchantment spells or effects. In the second, Asmodeus is purged of any diseases, poisons, or physical maladies (including lost body parts). In the third round, Asmodeus is healed to full hit points and feels refreshed as though he had just rested a full day, regaining spells and spell-like abilities accordingly. This ability triggers automatically if Asmodeus ever falls victim to a spell or spell like effect that would prevent him from taking actions.
• Asmodeus invades the mind of one creature within 240 feet of him. The creature must make a DC 25 Intelligence saving throw taking 55 (10d10) psychic damage on a failed save and half as much damage on a successful one. In addition, the target takes 22 (10d10) psychic damage at the end of each of its turns until it has attacked one ally twice or two allies once.
• Asmodeus conjures a cloud of burning ash that fills a 40-foot radius sphere centered on a point within 240 feet of him. The cloud spreads around corners, and is heavily obscured (not to Asmodeus). Each creature in the cloud when it appears, or that ends its turn in the cloud, must make a DC 25 Constitution saving throw, taking 54 (12d8) fire damage on a failed save, or half as much damage on a successful one. The cloud last for 1-minute and Asmodeus can use a bonus action to move it 30 feet.